The asymmetric unit of the title compound, [Fe(C5H5)(C5H4BrHg)], contains two independent molecules, A and B, in which the Hg—C bond lengths are 2.045 (6) and 2.046 (6) Å, the Hg—Br bond lengths are 2.4511 (9) and 2.4562 (7) Å, and the C—Hg—Br angles are 176.42 (17) and 177.32 (17)°. The two cyclopentadienyl rings of molecule A are eclipsed, while those of molecule B are almost staggered. The HgBr groups are connected by intermolecular Hg⋯Br contacts of 3.3142 (9)–3.4895 (11) Å, forming layers parallel to (001). These layers contain both four-membered (HgBr)2 and eight-membered (HgBr)4 rings. Ferrocene–ferrocene C—H⋯π contacts connect the molecular layers along the c-axis direction.